1. Field of the Invention
The present invention relates to the field of motor assemblies and more specifically to the area of improved methods of forming permanent magnets and assembling permanent magnets within a motor yoke.
2. Description of the Prior Art
Several patents discuss techniques employed to form ceramic permanent magnets from selected powder materials. For instance, U.S. Pat. Nos. 3,766,642; 3,830,743; 3,884,823; and 4,062,922, incorporated herein by reference, teach processes and formulations for preparing ferrite permanent magnets especially suited for use in small motor applications, due to the high coercive force and high remanence of such magnets.
The use of magnets, such as those described above, as well as other ceramic magnet materials in motor applications has involved the separate ceramic formation of the magnets as individual arc shaped elements that are subsequently installed within the conductive motor housing (yoke). U.S. Pat. Nos. 2,048,161; 2,513,227; and 3,083,310 illustrate typical methods of using wedges, clips and bolts to retain arc shaped magnets within the motor yoke. Recent improvements in adhesives have provided an alternative method for attaching magnets in place within the yoke.